Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of nitroglycerin on regional left ventricular performance, assessed by echocardiographic techniques, were investigated in anesthetized, open-chest dogs during acute myocardial ischemia. During transient occlusion of the left anterior descending coronary artery, there was end-diastolic thinning and marked reduction in systolic thickening in the central ischemic zone. Similar changes of lesser degree were noted in the border zone. The normal zone was unaffected. Infusion of nitroglycerin during ischemia in dosages of 2.5--50 microgram/kg/min reduced left ventricular end-diastolic pressure without changing the abnormalities of systolic wall thickening. Effects of bolus injections of 20 and 50 microgram/kg of nitroglycerin were similar, although this also lowered aortic pressure. In a subgroup of animals in which nitroglycerin infusion was unaccompanied by tachycardia, there was also no evidence that ischemic dysfunction was altered. We conclude that nitroglycerin does not improve regional myocardial performance in acutely ischemic canine myocardium. The decrease in preload is probably entirely due to the peripheral effects of the agent.
 ...
PMID:Effects of nitroglycerin on echocardiographic measurements of left ventricular wall thickness and regional myocardial performance during acute coronary ischemia. 10 86

The thickness of the left ventricular free wall and internal chamber diameter were continuously measured by pairs of ultrasonic crystals together with left ventricular pressure in normal conscious dogs. During the resting state, wall thickness decreased abruptly with the onset of atrial contraction from 10.5 mm to an average end-diastolic valueof9.8 mm. In contrast to most previous studies, there was no change in wall thickness during isovolumic systole, and with ejection the wall thickened by 31.3 percent of end-diastolic wall thickness. Atrial pacing, phenylephrine, isoproterenol and propranolol produced significant changes in chamber size with reciprocal changes in wall thickness. In addition, changes in the extent and velocity of left ventricular chamber shortening in the minor equator were associated with comparable reciprocal changes in the extent and velocity of free wall thickening (correlation coefficients 0.97 to 0.99). During acute coronary occlusion, progressive reductions in the extent and velocity of regional wall shortening with partial ischemia were associated with comparable changes in systolic wall thickening characteristics (r = 0.96 and 0.95), and holosystolic elongation in fully ischemic areas was associated with holosystolic wall thinning. During chronic pressure overload, despite wall thickening, the relation between chamber shortening and wall thickening were retained and direct computation of dynamic wall stress variations was possible. These measurements allowed precise definition of the dynamics of the left ventricular wall during normal and abnormal cardiac states. The demonstration that in the absence of regional dysfunction analysis of wall thickness in a single region of ventricular free wall can be used to describe myocardial and overall left ventricular function, as well as regional function in the presence of ischemia, constitutes a new approach to the assessment of cardiac function that has potential for echocardiographic applications.
 ...
PMID:Dynamic changes in left ventricular wall thickness and their use in analyzing cardiac function in the conscious dog. 13 93

Echocardiographic findings in patients with ischemic heart disease are described; their correlations with clinical, hemodynamic and angiographic data are presented and discussed. Regional abnormalities of left ventricular wall motion and/or thickening during systole are detected in 84 per cent of patients with acute myocardial infarction and in a high percentage of patients with larger than or equal to 75 per cent narrowing of a major coronary artery. These abnormalities may occur with stress and may be reversible. Left ventricular wall thinning during systole indicates acute ischemia or infarction and thin, dense myocardial echoes indicate scar. Echocardiographic evidence of left ventricular dysfunction is useful in predicting heart failure and mortality in patients with acute myocardial infarction and in predicting surgical mortality for patients undergoing aneurysmectomy and/or coronary artery bypass surgery. Echocardiography has not proved useful in determining graft patency following coronary artery bypass surgery. Technical difficulties and limitations of echocardiography in patients with coronary artery disease are discussed.
 ...
PMID:Echocardiography in ischemic heart disease. 32 1

Thirty-four patients with intermittent lower gastrointestinal bleeding were diagnosed angiographically as having angiodysplasia of the cecum and right colon. Repeated barium and endoscopic examinations were negative. Right colectomy was performed on 17 patients, who were followed postoperatively for up to 7 years. Of these, four patients rebled, two of whom had angiographic evidence of related lesions involving other parts of the colon and terminal ileum. Silicone rubber injection and tissue-clearing techniques on the specimens have facilitated the pathologic identification of these lesions. Histologically, they are dilated submucosal veins and arteries associated with areas of overlying mucosal thinning and occasional ulcerations. Although the pathogenesis of the lesion is unknown, we think they are acquired rather than congenital and result from chronic submucosal arteriovenous shunting secondary to mucosal ischemia. Of the 34 patients, 17 had a history of cardiac disease.
 ...
PMID:Angiodysplasia of the right colon: a cause of gastrointestinal bleeding. 41 Feb 41

Two hundred and eighty-four arteriograms were performed in the hands and feet 178 leprosy patients. Narrowing and tortuosity of the digital vessels, especially in the presence of bone absorption, were constant features. Digital tufts revealed signs of ischemia. However, in the presence of infection, hyperemia was a definite observation. Diminution in the caliber of the digital arteries and thinning or absence of the vascular end loops prove that ischemia plays a vital role in the production of various lesions in leprosy.
 ...
PMID:Arteriographic evaluation of vascular changes in leprosy. 62 20

To evaluate the influence of glucose infusate administered with insulin and potassium on left ventricular function during 4 h of ischemia, as well as mechanism of action, four groups of intact anesthetized dogs were studied. Acute regional ischemia was induced with a balloon tip catheter in the left anterior descending artery and infusates were begun after 20 min of ischemia. A threefold increase of plasma glucose concentration was associated with improved left ventricular function during ischemia, compared to animals receiving isovolumic saline. There was a significant decline of left ventricular end-diastolic pressure associated with elevation of stroke volume and ejection fraction to control levels, as determined by indicator dilution. In a separate subgroup studied by cineangiography, shortening of the ischemic anterior wall, after an initial decline, was increased in response to glucose but there was no evidence of extension of injury. Ischemic tissue exhibited a smaller gain of water as well as Na+ per gram dry weight as compared to ischemic controls. On precordial electrocardiogram mapping there was a significant decrease in the sigmaST (sum of ST elevation) as well as NST (number of ST segment elevations), but the reduction of R wave amplitude was not different from controls. To further evaluate long-term effects, eight controls and six treated animals underwent myocardial ischemia and were sacrificed after 4 mo. Calculated area and weight of scar, as well as degree of wall thinning, were similar in both groups. The glucose-treated animals had a significant decrease of plasma FFA in contrast to controls which manifested a significant rise. To examine the postulate that the decrease in FFA was important to therapeutic action, a third group was infused with Intralipid (Cutter Laboratories, Inc., Berkeley, Calif.) and heparin, simultaneously with the glucose infusate, to effect an elevation of plasma FFA during ischemia. Changes in myocardial function and electrolyte composition, as well as precordial electrocardiogram mapping, were similar to that of animals receiving glucose alone. Because serum osmolality was increased approximately 40 mosmol during the glucose infusion, the potential role of hyperosmolality was assessed by infusion of 20% mannitol during acute ischemia in a fourth group. After a transient small increase, there was a moderate decline in function by 4 h, suggesting that the response to glucose is not dependent upon extracellular osmolality. Thus, it is concluded that during the initial hours after the onset of myocardial ischemia the glucose infusate improves ventricular performance without evidence of arrhythmia induction or intensification of ischemic injury. Evolution of irreversible necrosis appears to be delayed rather than prevented under the circumstances of this study.
 ...
PMID:Sustained effect of glucose-insulin-potassium on myocardial performance during regional ischemia. Role of free fatty acid and osmolality. 65 87

Echocardiographic septal and posterior wall thicknesses and the percent change with systole were measured in 146 patients with the following diagnoses: acute myocardial infarction (40), chronic coronary artery disease (49), congestive cardiomyopathy (8), atrial septal defect (20), and no cardiac disease (29). Mean diastolic thicknesses for the groups of patients with coronary artery disease and congestive cardiomyopathy were not significantly different from normal although there were abnormal values for individual patients within each group. Mean diastolic thickness of the septum was greater than normal for the group with atrial septal defect (P less than 0.02). Wall thinning with systole was associated with acute infarction or ischemia (P less than 0.0001); decreased thickening (less than normal) commonly occurred in patients with acute myocardial infarction, chronic coronary artery disease, and congestive cardiomyopathy. Patients with atrial septal defect had normal thickening with abnormal motion. Results of this study show that 1) systolic thinning is indicative of an acute event; 2) abnormal changes in systolic wall thickening occur commonly in patients with coronary artery disease or congestive cardiomyopathy; and 3) abnormal wall motion may occur without abnormal wall thickening, as the echoes of patients with atrial septal defect indicate.
 ...
PMID:Systolic thickening and thinning of the septum and posterior wall in patients with coronary artery disease, congestive cardiomyopathy, and atrial septal defect. 83 Jan 97

The pathogenesis of acute gastric mucosal lesions produced by distension of the rat stomach was studied. One hour of distension with 0.1 N HCl, but not saline, produced lesions in the glandular stomach in all rats. Histologic studies revealed marked thinning of the mucosa plus thrombus formation in the ulcerated area. Gastric distension with 8 ml HCl (per 100 g body weight) produced severe lesions, 4 ml minimal lesions and 2 ml no lesions. Intragastric pressure in the 8-ml group remained above 110 mm H2O for the first 10 min. Distension with 8 ml acid/100 g body weight for just 10 min resulted in significant lesion formation. Acid distension did not cause generalized disruption of the gastric mucosal barrier to H+ back-diffusion. It appears that an intragastric pressure of over 110 mm H2O for 10 min damages the mucosa by pressure (with thinning) and ischemia (with thrombosis), resulting in decreased resistance to acid peptic digestion and consequent acute lesion formation.
 ...
PMID:Mucosal lesions due to gastric distension in the rat. 93 Sep 7

To determine whether modulation of systolic ventricular interaction influences right ventricular performance during right heart ischemia, the effects of septal ischemia and inotropic stimulation were studied in 15 dogs in an open chest preparation. Right coronary branch occlusions led to right ventricular dilation and free wall dyskinesia, reversed septal curvature and reduced left ventricular diastolic volume. In systole, the septum thickened but bulged paradoxically into the right ventricle generating an active but depressed right ventricular systolic pressure (28.9 +/- 5.5 to 22.1 +/- 4.5 mm Hg), with associated decreases in right ventricular stroke work (5.66 +/- 0.94 to 1.92 +/- 0.53 g.m/m2) and left ventricular systolic pressure (123 +/- 11 to 80 +/- 10 mm Hg). Septal ischemia induced systolic septal thinning, left ventricular dilation and decreased left ventricular systolic pressure (80 +/- 10 to 55 +/- 10 mm Hg) and stroke work. Although the extent of paradoxic septal displacement increased, there were further decrements in right ventricular systolic pressure (22.1 +/- 4.5 to 18.7 +/- 4.3 mm Hg) and stroke work (1.92 +/- 0.53 to 0.7 +/- 0.2 g.m/m2). Dopamine infusion augmented left ventricular free wall contraction and increased left ventricular systolic pressure (55 +/- 10 to 172 +/- 17 mm Hg) and stroke work. Although systolic septal thinning persisted, the extent of paradoxic septal displacement increased strikingly and, despite continued right ventricular free wall dyskinesia, right ventricular systolic pressure increased (18.7 +/- 4.3 to 39.6 +/- 6.2 mm Hg) as did right ventricular stroke work (0.7 +/- 0.2 to 7 +/- 1.6 g.m/m2).(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Importance of left ventricular function and systolic ventricular interaction to right ventricular performance during acute right heart ischemia. 153 32

To assess the effects of left ventricular chamber volume on the mechanism of changes in left ventricular developed pressure we performed phosphorous-31 nuclear magnetic resonance spectroscopy, hydrogen-1 nuclear magnetic resonance spectroscopy with a shift reagent, two-dimensional echocardiography, atomic absorption spectrophotometry, microsphere analysis, and surface fluorometry on isovolumic isolated perfused rat hearts with incremental intraventricular balloon volumes, while left ventricular pressure was concurrently monitored. A three-phasic response of developed pressure was noted: 0 to 100 microliters balloon volumes resulted in an increase in developed pressure, whereas developed pressure remained constant at 250 microliters and fell at 400 microliters. Oxygen consumption and [Ca2+]i transients followed the same pattern as developed pressure and coronary flow. Intraventricular volumes of 250 microliters or greater (a volume overload) caused endocardial ischemia, a greater decrease in extracellular versus intracellular water, thinning of the left ventricular free wall, and an increase in chamber size. Mechanical pressure on the tissue, induced by the volume overload, caused ischemia as further evidenced by (1) a negative effect on developed pressure, (2) a decrease in [Ca2+]i transients, (3) a [Ca2+]i overload, (4) a moderate decrease in the phosphorylation potential, and (5) an increase in the oxidation-reduction state (nicotinamide-adenine dinucleotide). The high intracellular calcium associated with volume overload may have been due to both compression and ischemia, which leads to an increased number of cross-bridges in rigor, a high end-diastolic pressure, and an increase in wall stress.
 ...
PMID:Mechanism for depressed cardiac function in left ventricular volume overload. 199 Jul 59


1 2 3 4 5 6 7 8 9 10 Next >>